A method for the production of a porous powder product containing a microorganism, from a liquid concentrate comprising at least one liquid microorganism culture and a carrier composition is disclosed. The carrier composition comprises at least one carbohydrate and at least one protein. The method comprises steps of preparing the liquid concentrate to a temperature of between 5 and 40°C to have a viscosity greater than 150 mPa.s at that temperature； injecting a food grade gas into the prepared concentrate at a pressure greater than 0.3 MPa to intimately incorporate the gas into the liquid concentrate and form a stable foam with a density of between about 0.6 to about 1.2 kg/l； conveying the foam to an atomizing device where the pressure of the foam is reduced from 0.3 MPa to atmospheric pressure to provide a partially dried product； and exposing the partially dried product to a drying media to reduce both the moisture content to less than 5% moisture and the water activity to less than 0.25 Aw, to provide the porous powder product. The porous powder product contains high levels of viable microorganism, while avoiding difficulties associated with freeze drying and high temperature techniques.
